Atmospheric heat source/sink response to the snow depth over the Tibetan plateau in melting season: A modeling study

Atmospheric heat source/sink (AHS) of the Tibetan Plateau (TP) is strongly linked to the local snow depth. Based on the numerical simulations with Weather Research and Forecasting (WRF) model, connections between snow depth and the AHS across the TP in melting season (May-August) are investigated. Compared with the derived AHS from reanalysis data, spatial patterns and monthly evolution of the AHS are reasonably reproduced by the WRF model. The AHS can be significantly reduced (similar to 80 W m(-2)) by snow over both the western and southeastern TP in early May, which is mainly ascribed to the weakened surface sensible heat (SH) and atmospheric latent heat. Obvious cooling effect of snow on the AHS is still found over the western TP even in mid-summer. However, the cooling strength in late summer has declined to one-fifth that of May and it is totally dominated by the reduced surface SH. As to the southeastern TP, snow is thin and scattered since June, resulting that the AHS response to snow depth declines significantly and even vanishes in mid-summer. It is further clarified that there is no elevation-dependent relationship between the AHS and snow over the TP, while the cooling amplitudes of the AHS varied with altitude are mainly determined by the corresponding snow depth.